A comparison study of hydrogen storage performances of as-milled YMg11Ni alloy catalyzed by CeO2 and MoS2

The microstructures, hydrogen storage thermodynamics and kinetics, and non-isothermal dehydrogenation performances of YMg11Ni + 5 wt% M (M = CeO2, MoS2) alloys prepared by ball milling were investigated. The results reveal that there exist a nanocrystalline and amorphous structure in all experimental alloys. The CeO2 catalyzed alloy shows a larger hydrogen absorption capacity and faster hydriding rate as compared with the MoS2 catalyzed one. The onset hydrogen desorption temperature of M = CeO2 alloy is lower than that of M = MoS2 alloy. The hydrogen desorption property of M = CeO2 alloy is superior to that of M = MoS2 alloy. The dehydrogenation activation energy (Ede) is in the order of Ede(CeO2) < Ede(MoS2), which is responsible for the M = CeO2 alloy possessing the much faster hydrogen desorption rate. The hydrogen desorption enthalpy change (ΔHde) is in the order of ΔHde(CeO2) < ΔHde(MoS2).